Distribution of the bulge-to-total ratio (B/T) of our LSB galactic sample. Here, the B/T is derived from the parameter “fracDevr” from the SDSS DR7 catalog, which represents the fraction of r-band luminosity contributed by the bulge relative to the luminosity contributed by all components (bulge + disk) of galaxies. The dashed black line shows the bulge-to-total ratios of the 1129 galaxies of our LSB galactic sample. For comparison, the B/T distribution of the 12,423 galaxies of our parent sample is overplotted as solid gray. Both histograms are normalized to have a maximum value equal to 1.0 for a clear comparison.